TTI
Transmission Time Interval
This is defined as the inter-arrival time of TBS (Transport Block Set), and is equal to the periodicity at which a Transport Block Set is transferred by the physical layer on the radio interface. It is always a multiple of the minimum interleaving period (e.g. 10ms, the length of one RF (Radio Frame)). The MAC (Medium Access Control) delivers one Transport Block Set to the physical layer every TTI.